On a Wednesday 5 pm, the facility air conditioning suffered fire damage. The optimistic (O), most likely (M), and pessimistic (P) times of the activities of its repair project are shown in the table below. Work hours are 8 am to 5 pm Monday through Friday.

If the repair job commenced at 8 am on Thursday, the day and time of its expected completion, the probabilities that the project would be completed in duration of a) four workdays and b) six workdays, respectively, are:

Predecessor O, M, Activity P, hours activity hours hours 1: Report, clean up, test, order parts 6 8 12 2: Review higher-up's inputs/approval 4 24 36 3: Assemble replacement parts 1 3 6 9 4: System leak check and test 2, 3 6 9 11 5: Draft repair report and document 1 2 4 6 6: 2nd test and fill data in the report 5 2 4 6 7: Submit report, bills, process payment 4, 6 4 7 12